Quick releasing safety crane hook



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QUICK RELEASING SAFETY CRANE HOOK Filed Dec. 14, 1945 2 Sheets-Sheet lgvwwwbo o HMRULD M. GULBERT T R E B m G H H QUICK RELEASING SAFETY CRANEHOOK 2 Sheets-Sheet 2 Filed Dec. 14, 1945 T. W E B M W G Patented May30, 1950 its rrss

TENT FHQE Application December 14, 1M5, Serial No. 634,959%

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3'700. G. 757) 9 Claims.

This invention relates to a device for connecting one member to anotherfor quick release and more specifically to a quick release hookassociated with hoisting tackle for securely supporting a load duringmanipulation thereof but permitting quick release wh n desired.

In launching landing craft from a ship into the water, it is desirableto employ a quick release hook at the lower hoist block rather than theconventional open hook because the ring and slings, by which the landingcraft suspended from the hook and hence the hoist block, are very heavy,and it is diilicult and hazardous for one to lift the ring off the hookespecially when the craft is being tossed about by the surf. A quickrelease hook is likewise desirable wherever hoisting tackle is employedfor transferring a load from one place to another since there is alwaysthe danger that the operator will be injured in disengaging the slingsor similar tackle attached to the load from the hook. It is an object ofthe invention therefore to provide an improved type of quick releasesafety hook for securing a load to a conventional hoist block, thedesign of the hook being such that it will be secure but readilyreleasable and simple in construction.

In its broader aspect, novelty resides in a device for releasablyconnecting one member to another, for example, a hoist block to tackleattached to a load comprising a bar from which the tackle is suspendedone end of which is pivotally connected to the hoist block and the freeend of which is adapted to releasably be locked to the hoist blockwhereupon release of the free end of the bar from the block will allowthe tackle supported hereby to slide oil. As illustrated, the bar ispivoted between the lower ends of a pair of links, the upper ends ofwhich are pivctally attached to the bottom side of the hoist block, andits free end is releasably supported at substantially the same level asits pivoted end by a bearing block fixed between the lower ends of asecond pair of links also pivotally attached to the hoist block. Akeeper pivoted adjacent to the free end of the bar on the second pair oflinks is adapted to bear against the same and to hold it in engagementwith the bearing block and hence against movement normal to the bearingblock. The bearing block and bar have interlocking mating surfaces sothat when they are held in engagement by the keeper movement of thebearing block laterally with respect to the bar is prevented. A baleshaped lever is connected to the aforesaid keeper and serves initiallyto move the same to an out of the way position and upon further movementto swing the second pair of links about their pivot 2 to move thebearing block laterall from beneath the end of the bar. Associated withthe hoist block is a stop adapted to prevent the pairs of links frommovement inwardly toward each other or distortion of the Whole device inone direction or the other and associated with one pair of links is astop adapted to limit tilting movement of the bar about its pivoted endwhen its free end is released from support by the bearing block.

The invention will now be described in detail references to theaccompanying drawing in which:

Figure l is a side elevation showing the invention as employed with ahoist block and tackle for releasably suporting a landing craft from aring and sling;

Figure 2 is a side elevation of the quick release hook partly brokenawayand showing the ring to which the sling is attached supported on the barand;

Figure 3 is an end view taken from the left side or the hook as seen inFigure 2.

Referring to Figure 1, there is illustrated a landing craft H} which isprovided with ropes 12 attached at one end to eyes it fixed to thelanding craft and at their opposite ends to a ring it. The ropes l2 andring it constitute what is ordinarily known as a sling by which thelanding craft is suspended from a hook til, the hook in turn being fixedto the lower block it of a block and tackle. The hook it which forms thesubject matter of this invention is of the quick release type, thedetails of which will now be described.

Referring to Figure 2, the lower block if! of the block and tackle is ofthe usual construction having a pair of spaced walls 22 (Figure 3). Inthe lower portion of the walls 22 pairs of the opposed openinsg 24 areformed which are adapted to receive the opposite ends of a pair of bolts2%. The bolts 25 are retained in place by washers 28 which engage theoutside of the block and cotter pins 30. Between the walls 22 two pairsof links 32 and 3d are suspended on the bolts 25 and are held in spacedrelation by collars (56 disposed on the bolts between the links. At thelower ends of one of the pairs of links 32, there are formed openings 38for receiving pin it and on this pin ill there is pivotally mounted abar. The opposite end of the bar G2 is enlarged to form a mad lit andhas on its lower side a concave surface and on its upper side concavesurface 53. A hearing block 56 having a convex surface 52 is fixedbetween the lower ends of the other pair of links 34 as by a pin is in aposition to be engaged by the concave surface M on the lower side of thebar 42 and hence to support this end of the 3 bar. A bolt 55 is mountedbetween the links 34 above the free end of the bar 42 and on this boltthere is pivotally mounted a bar 54, the lower or outer end 48 of whichis convex and is adapted to cooperate with the concave surface 58 of theupper or inner side of the bar 42. When the keeper 54 is hanging in asubstantially vertical position from its pivot bolt 56, the lowersurface 48 thereof will engage the surface 58 of the bar 42 and preventmovement of the free end of the bar 42 normal to the supporting surface52 and will also prevent outward lateral movement of the links 34 withrespect to the head of the bar 42. Thus the bar 42 is locked to thelinks 34 so that the ring I6 is held in place. In order to release thebar 42 and in turn to release the ring I6 so that the landing craft maybe released from the block and tackle, means is provided for moving thekeeper 54 to an out of the way position. This comprises a pair of arms6t pivotally attached by a bolt 62 to the keeper 54 at one end and attheir opposite ends to a pair of arms $5. The arms 66 are pivotallyattached by bolts 68 to the spaced links 34. These arms form acontinuation of a bail shaped member iii which constitutes a handle andare integral therewith. By pulling he handle IS in a clockwise directionabout its pivot bolts 58 the arms 63 are caused to move upwardly and tothe left which swings the keeper 54 clockwise about its pivot bolt 55 toan out of the way position as shown in dotted lines. Further movement ofthe handle 'lEl will swing the links 34 in a clockwise direction todisengage the support 52 from the convex surface 44 and hence from thehead 4* of the bar 42. In order to prevent swinging of the links 32 inresponse to the pull on the handle IQ and to prevent distortion of thewhole coupling due to side sway a stop 78 in the form of a plate isfixed between the two pairs of links to the underside of the hoist blockin a position to engage and prevent swinging movement of either pair oflinks toward the other. A stop 12 is also provided for preventing thebar 42 from tilting more than just enough to allow the ring it to slideoff easily. The stop '52 comprises a plate fixed between the links 32and its lower edge 74 is adapted to engage the rear end E6 of the bar 42as soon as the bar has tilted a predetermined amount.

In operation of the device, that is to release the bar 42 from itslocked position as shown in Figure 2, the operator grasps the handle iiiand swings it the left as seen in Figure 2 about its pivot points on thebolts 38. The initial movement of the arms (56 move the arms 60 to theleft and upwardly so as to swing the arm 54 in a clockwise directionabout the bolt 56. As soon as the keeper 54 has moved to an out of theway position as shown in dotted lines the bar 42 is, of course,unlocked. Further movement of the handle 70 to the left will then swingthe links 34 about the bolt 26 thereby to disengage the supportingsurface 52 laterally from beneath the convex surface 44 of the bar. Assoon as the head 46 of the bar 42 is withdrawn from the links 34 theweight of the landing craft and tackle will cause the bar 42 to tiltdownwardly until its rear end 15 engages the stop 14 whereupon the ringIE will slide toward the head of the bar and in doing so will push thelinks 34 ahead of it. The ring [6 upon clearing the head of the bar 42will fall away from the bar, hence releasing the landing craft and thelinks 34 will then swing back into contact with the end of the bar 42.

In the claims the terms inner and "outer are used alternatively withupper and lower respectively, as referring to the hook position of Fig.2.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

I claim:

1. A device for releasably supporting a load comprising a bar from whichthe load is suspended, first link means for pivotally supporting one endof the bar, second link means arranged to engage the outer side of freeend of the bar to hold it at substantiall the same level as the pivotedend, a keeper means releasably engaging the inner side of said free endof the bar to hold the outer side of the bar against the second linkmeans, actuating means for moving the keeper means to a position out ofengagement with the inner side of the bar and th reafter moving saidsecond link means laterally from beneath the under side of the bar.

2. In combination with a block and tackle, a hook for releasablysuporting a load from the block comprising a plurality of pairs ofspaced members pivotally suspended from the block, a bar pivotallyattached to one pair or members, a bearing block attached to the secondpair of members upon which the free end of the bar is adapted to rest, akeeper pivoted on said second pair of members, the outer end of which isadapted to engage and hold the free end of the bar against movementnormal to the bearing block and hence to lock the bar in a substantiallyhorizontal position, a toggle linkage on the secand pair of members formoving said keeper to an out of the way position and said second pair ofmembers laterally to move the bearing block out of engagement with thefree end of the bar and a stop on said first pair of members adapted tolimit the tilt of the unsupported end of the bar a predetermined amount.

3. In combination with a block and tackle, a hook for releasablysupporting a load from the block comprising two pairs of parallel linkssuspended from the under side of the block and spaced from each other, abar pivoted between the lower ends of one pair of links, a bearing blockhaving an upper curved bearing surface fixed between the lower ends ofthe other pair of links, said curved surface being adapted to engage andsupport the free end of the bar at substantiallythe same level as thepivoted end of the bar, and

said bar having a surface mating with said curved supporting surface, akeeper pivoted on said second pair of links adapted to hold the bar inengagement with the curved supporting surface or the block thereby toprevent both normal and lateral movement of the bar with respect to thesupport block and means for moving said keeper to an out of the wayposition to release the bar, said means serving also to swing the secondpair of links ina direction to move the support block laterally frombeneath the end of the bar and means to prevent movement of the firstpair oi links in the direction of the applied force.

4. A device for releasabl connecting one mem-' her to a second member,comprising a bar engageable with the second member, a pair of linkspivotally secured to the first of said members to pivotally support oneend of the bar, a second pair of links pivotally mounted on said firstmember to support the free end of the bar, a keeper for holding said barin engagement with the second pair of links, and a toggle linkage forreleasing the keeper from the bar and moving said second pair of linksto a position of non-support of the bar permitting the bar to dropdisengaging the load.

5. A device for releasably supporting a load comprising a body member, abar from which the load is suspended, first link means carried by thebody member for pivotally supporting one end of the bar, second linkmeans pivotally connected to the body member for supporting the free endof the bar, a keeper for locking said bar in engagement with said secondlink means, and a toggle linkage for moving said keeper to a position tounlock the free end of the bar from its supporting link means to freethe load.

6. A device for releasably supporting a load comprising a bar from whichthe load is suspended, first link means pivotally supporting one end ofthe bar, second link means pivotally engaging the outer side of the barto hold it at substantially the same level as the pivoted end, a pivotedkeeper engaging the inner side of the bar to prevent lateral movement ofthe second link means with respect to the bar, and a toggle linkage todisengage the keeper from the bar to free the load.

7. A device for releasably supporting a load comprising a, bar fromwhich the load is suspended, first link means pivotally supporting oneend of the bar, a curved surface on the outer side of the bar, secondlink means having curved surfaces complementing the surface Of the barfor holding the free end of the bar at substantially the same level asthe pivoted end, a keeper for holding said mating surfaces inengagement, and means for releasing the keeper to free the matingsurfaces whereby movement of the bar is permitted.

8. A device for releasably supporting a load comprising a bar from whichthe load is suspended, a pair of links pivotally supporting one end ofthe bar, a, second pair of links engaging the underside of the free endof the bar, a keeper releasably engaging the top of the free end of thebar to hold it in contact with the second pair of links, toggle meansfor moving the keeper out of engagement with the bar and for moving thesecond pair of links to permit the bar to drop about its pivot to freethe load, and a stop for limiting the movement of the bar.

9. A device for releasably connecting a first member to a second member,comprising a bar engageable with the second member, first link meanssecured to the first member to support permanently and pivotally one endof the bar, second link means pivotally mounted on said first member tosupport detachably the free end of the bar, a keeper for holding saidbar in engagement with the said second link means, and preventing axialand lateral displacement thereof and actuating means for releasing thekeeper from engagement with the bar and moving said second link means toa position of non-support of said bar whereby said second member isdisengaged.

HAROLD H. GILBERT.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 472,353 Hilton Apr. 5, 18921,079,297 Jacques Nov. 18, 1913 1,251,531 Hunt Jan. 1, 1918 FOREIGNPATENTS Number Country Date 481 Great Britain Mar. 10, 1858

